Jana Tkáčová

Honey characteristics after extraction and half-year storage

The aim of the study was to analyze the fresh honey after extracting and after half-year storage at room temperature. Overall, we analyzed 10 samples of rape ( Brassica napus ) honey coming from district Vranov nad Toplou located in the eastern Slovakia. The analysis consisted of the evaluation of the physico-chemical parameters (water content, free acidity and electrical conductivity) and microbiological evaluation (total plate count (TPC), counts of coliform bacteria, lactic acid bacteria, sporulating microorganisms and microscopic fungi). Water content, free acidity and electrical conductivity were measured according to IHC (2009), namely these parameters were detected by refractometer, titration and conductometer, respectively. We used dilution plating method for microbiological analysis. Fresh rape honey contained 18.3 ±1.0% of water. Free acidity of fresh rape honey was 12.7 ±2.0 meq.kg -1 and electrical conductivity was 0.14 mS.cm -1 . After half a year of storage, water content and electrical conductivity decreased nonsignificantly and free acidity increased nonsignificantly. Stored honey samples meet the requirements of Decree 41/2012 and 106/2012. From microbiological point of view, fresh rape honey showed relatively high microbial counts. Mean values of TPC, sporulating microorganisms, lactic acid bacteria and yeasts exceeded 2.00 log cfu/g. All spotted microbial groups decreased in the stored honey comparing with the fresh honey. We found significant ( p ˂0.01) differences of TPC, lactic acid bacteria and yeasts comparing the fresh and stored honey samples. Evaluating microbiological parameters, one sample of stored honey did not meet the requirements of Codex Alimentarius SR (2014). TPC exceeded the limit value. Based on the results we can conclude that all samples meet the requirements for good quality honey. Microbial counts in the honey decreased gradually. Probably, various microorganisms have important role in creation of the honey from the nectar of plants, but non-sporulating microorganisms die in the ripe honey.

Protein quality chicken meat after feeding with active substances of citrus fruits and diclazuril and salinomycin sodium

The purpose of this study was an experimental investigation of the influence of active substances obtained mainly from citrus fruits in the experimental feed mixtures, and diclazuril and salinomycin sodium in the control feed mixtures of broiler chickens on productive efficiency and protein quality of the breast and thigh muscles. In vivo experiment was carried out with hybrid chickens Cobb 500. Basic feed mixtures were equal a soy cereal type for experimental and control group. Indicators of productive efficiency were measured and calculated, and protein, lysine and methionine contents in the breast and thigh muscles were measured by the method of FT IR, Nicolet 6700. Active substances obtained mainly from citrus fruits confirmed a statistically significant (p ˂0.05) positive effect on the body weight gain; tended to slightly increase feed intake per bird, protein, energy, lysine and methionine intake per bird; slightly decrease feed intake per 1 kg of body weight gain, protein, energy, lysine and methionine intake per 1 kg of body weight gain; slightly increase protein efficiency ratio and energy efficiency ratio. Additive substances used in the feed mixtures did not have a statistically significant effect on protein, lysine and methionine contents in the breast and thigh muscles but displayed a strong positive, statistically significant relation between lysine and methionine in them.

The investigation of alfaalfa effect on the activity of superoxide dismutase in chicken meat in dependence on time storage

This study was conducted in order to monitor the effect of adding lucerne meal to chicken feed mixtures. The experiment was conducted at the Department Food Hygiene and Safety, Faculty of Biotechnology and Food Science, Slovak University of Agriculture in Nitra. Chickens for meat production - final type Cobb 500 were used in the experiment. Chickens were placed in boxes all together for one group at the beginning of the experiment and from 14 days of age chickens were divided individually into floor enriched cages. Feeding of chickens lasted 38 days. The experiment was carried out without sex segregation. For the production of a feed composition was used alfalfa ( Medicago sativa ) as lucerne meal, which was added to the feed at a rate of 4%, namely: starter (HYD-01), growth (HYD-02) and final (HYD-03). The control group did not include the addition of lucerne meal. Chickens were fed ad libitum . Chickens were slaughtered after completion of feeding and the meat samples were taken for analysis. The collected samples were stored at -18 °C. Collected samples of meat were analyzed after slaughter chickens at time intervals of 6, 12 and 18 months. In the experiment was monitored the content of supeoxid dismutase in the chicken meat depending on the length of storage time. Superoxide dismutase content was increasing by storage time, while there were some statistically significant differences between groups. Normal 0 21 false false false SK X-NONE X-NONE

Nitrate and nitrite contents in in the private ground water wells

The aim of the study was to investigation and statistical evaluation of nitrate and nitrite in ground sources of drinking water, particularly in private wells and springs in the surroundings of town Nitra, in the river basin Žitava. Samples were taken in the spring month May and the autumn month October of the same water sources. The contents of nitrate and nitrite was determined by test strips QUANTOFIX Nitrate and nitrite. The results were evaluated in the system SAS program, version 8.2. The difference of nitrate in drinking water sources between spring and autumn months was statistically evaluated by t-test. The nitrate content in drinking water samples taken from the surroundings of town Nitra, in the river basin Žitava, was measured in the spring month of May with exceeding values that exceeded the 50 mg.L-1, which is the limit value for the adult human population, in the well of municipalities Veľka Maňa, Žitavce, Michal nad Žitavou, Mala Maňa, Uľany nad Žitavou, Hul, Kmeťovo and 50 mg.L-1 was measured in spring Vlkas, in well of municipality Lucnica nad Žitavou, Veľka Maňa, part of the Stara Hora. In the autumn month October measured nitrate content was reduced in samples taken in the municipalities Lucnica nad Žitavou, Mala Maňa, Kmeťovo and Uľany nad Žitavou. The difference of nitrate content in water from water sources investigated in surroundings of town Nitra was not statistically significant (p >0.05) between the months May and October. The nitrite content in the same water sources in the surrounding of town Nitra was not detected.

Effect of thyme and oregano aqueous tea infusions on the lipid oxidation and sensory characteristics of frankfurkters sausages

Lipid oxidation is one of the main limiting factors for the quality and acceptability of frankfurkter type of sausages. The antioxidant activity has been measured using a TBA assay. Dried oregano ( Origanum vulgare ) and thyme ( Thymus vulgare ) were purchased from a local store and kept in dark until the use. Aqueous extracts were prepared by one-step extraction with 3 g of each pulverized plant. Samples of freshly cooked sausages were evaluated by a 6 member semi-trained panel of laboratory co-workers. Panelists evaluate appearance overall texture, flavour, aroma and overall acceptability on a 6 point hedonic scale. In this work the antimicrobial and antioxidant effect of Thymus vulgare and Origanum vulgare significantly reduced ( p <0.05) lipid oxidation in frankfurkters sausages on 10th day of aerobic storage. The organoleptic changes in sausages had no negative effect on the sensory value of cooked sausages. Results obtained in this work indicated the technical viability of using the oregano and thyme aqueous tea infusions in relative low concentration, which is possible to enlarge the shelf-life of fresh sausages with the desired slight alteration of the original taste parameters. Results indicate that thyme and oregano aqueous tea infusions compare to essential oils can be cheaper alternative incorporate into pork frankfurkters as natural antioxidants. Normal 0 21 false false false EN-GB X-NONE X-NONE

Effect of grape seed extract on quality of raw-cooked meat products

In the present study we aimed to evaluate the oxidative stability of Spis frankfurters after application of grape seeds extracts (Blauburger + Cabernet Sauvignon and Danube) in amount of 10 mL.kg -1 during 12 days of their storage at 4 °C. Sensory evaluation of Spis frankfurters was carried out after 4 days of storage by 6-point ranking system (Surface appearance and color, appearance and color when cut, texture, aroma and flavor). It was found that sensory quality of Spis frankfurters was not significantly ( p >0.05) affected by application of grape seed extracts. Oxidation stability of Spis frankfurters after 12 days of storage at 4 °C was positively influenced ( p ≤0.05) only in the group with addition of extract made from grape seed Blauburger +Cabernet Sauvignon. This may probably related with the higher antioxidant activity of extract of this variety (100.5%) compared to an extract made from grape seed variety of Danube (55.8%). Also, it was not found significant differences ( p >0.05) of antioxidant activity between extract made from grape seeds variety Danube compared with the control group. Normal 0 21 false false false SK X-NONE X-NONE

Relation between selected nutrients in the chicken meat depending on phytogenic feed additives

The aim of study was to evaluate the relation between selected nutrients in the breast and thigh muscles after the application of different phytogenic additives in the diet of broiler chickens and between same indicators of meat disregarding additive and parts of carcass, from which muscles originate. We realized an in vivo experiment on the Zamostie Company poultry test station with deep litter breeding system. The experiment included 100 pcs of one-day-old hybrid chickens Cobb 500 divided into 2 groups (n = 50): the 1st experimental group with an application of feed additive from chestnut tree and lemon fruit extracts and the 2nd experimental group with an application of feed additive from citrus fruits extract. We used a cereal and soybean basal diet and we divided the fattening period into four phases: starter (1 - 10 days), grower I (11 - 20 days), grower II (21 - 28 days) and finisher (29 - 42 days). We applied a powder form feed mixtures. Nutritive value of feed mixtures was the same in each experimental group during the whole experiment and in accordance with the physiological needs of broiler chickens. We fed the 1st experimental group with a basal diet enriched by feed additive from chestnut tree and lemon fruit extracts (50 g/100 kg). As for the 2nd experimental group, we applied feed additive from citrus fruits extracts through the drinking water (100 mL/100 L). In the 2nd part of our experiment, we compared results obtained from two experimental groups with other four groups of diet. We applied other phytogenic additives to these four groups and we did not take into account the origin of the meat sample. We measured indicators of the chemical composition of protein, fat, water and cholesterol on a sample (50 g) of breast and thigh muscle without skin by the method of FT IR by use of the apparatus Nicolet 6700. Detected relations between nutrients of breast and thigh muscles were defined by correlation coefficient of -0.6 ≤ r ≥ +0.6. When additive with chestnut tree and lemon fruit extracts was used, we detected a negative correlation (p ≤0.01) between protein and cholesterol of breast muscle. In thigh muscle, the negative correlation was observed between protein and energy (p ≤0.05), protein and fat (p ≤0.01) as well as fat and water. The only positive correlation was detected between protein and cholesterol of breast muscle (p ≤0.01), with additive citrus fruits extract. When nutrition and parts of carcass, from which muscles originate, were disregarded, protein of meat increased, energy and fat decreased (p ≤0.001). When fat of meat increased, energy increased (p >0.05) as well, but water decreased (p ≤0.05; p ≤0.001).

Amino acid profile of broiler chickens meat fed diets supplemented with bee pollen and propolis

The objective of this study was to evaluate the effects of diets supplemented with bee pollen and propolis on the amino acid (AA) profile of chicken meat. A total of 360 one day-old Ross 308 broiler chicks were randomly assigned to three treatments: a basal diet without supplementation as control (C); a basal diet supplemented with bee pollen extract (400 mg kg−1 of feed mixture: E1); and a basal diet supplemented with propolis extract (400 mg kg−1 of feed mixture: E2). Chickens were slaughtered at 42 d of age. After slaughter, the AA profile of breast and thigh samples was determined. The data were analyzed using analysis of variance. The AA profile was not affected by dietary bee pollen supplementation (E1) in breast and thigh muscles (disregarding sex), except for higher concentration of Tyr (p ≤ 0.05) in breast and lower concentration of Pro (p > 0.05) in breast and thigh muscles compared with those in C. However, the AA profile was improved in response to propolis supplementation (E2). In breast muscle (disregarding sex), the highest concentrations of Glu (11.81 g 100 g−1), Gly (3.5 g 100 g−1), and Tyr (4.12 g 100 g−1) were found in the propolis-supplemented group (E2), Glu and Tyr were higher (p ≤ 0.05) in E2 compared with those in C, while Gly was higher (p ≤ 0.05) in E2 compared to E1. Additionally, many other AAs (Asp, Ser, Ala, Tyr, Arg, Thr, Ile, Leu, Phe, and Lys) were observed as the highest (p > 0.05) in breast muscle of broilers fed a diet with propolis extract (E2). In thigh muscle (disregarding sex), higher concentrations (p ≤ 0.05) of Tyr (2.46 g 100 g−1) and His (2.35 g 100 g−1) were found in the propolis-supplemented group (E2) compared with those in C. Many other AAs (Glu, Gly, His, Arg, Thr, Val, Ile, Leu, and Lys) in thigh muscle from propolis-supplemented group (E2) were also higher (p > 0.05) than those in the other groups. After bee pollen (E1) and propolis (E2) supplementation, no differences in amino acid concentrations between males and females, or in breast or thigh muscle were found. In general, breast was demonstrated to contain higher proportions of AAs than thigh muscle. In conclusion, dietary propolis supplementation in amount of 400 mg kg−1 of feed mixture elicited the best AA profile of chicken meat among the dietary treatments and may thus be a promising method to improve meat quality.

The effect of dietary alfalfa meal on the chicken meat quality

The purpose of this study was to investigate the effect of feed mixtures with proportion of alflafa meal 4% on body weight of broiler chickens, fat content their meat and oxidative stability meat fat under storage conditions. Final hybrid Cobb 500 chickens were used in the experiment. The broiler chickens were fed with feed mixtures starter from the 1st to the 18th day, grower from the 19th to the 31st day and finisher from the 32nd to the 38th ad libitum. An alfalfa meal of 4% was added in the feed mixtures of experimental group. In our experiment, we used alfalfa meal, which was made from Medicago sativa L. harvested in the buds phase. The carcasses of broilers were stored at -18° C for a period of nine months. The average weight of chickens at the end of our experiment, the control group was 1685.6 g. In experimental group with addition of 4% alfalfa meal in feed mixtures, the chickens weighed 1709.6 g. The difference in body weight between the groups was not statistically significant ( p >0.05). The average fat content in chicken meat was lower in the group with a share of 4% alfalfa meal 2.33 g.100g -1 compared to the fat content in meat chickens control group 2.59 g.100g -1 . Differences in fat content in meat between the groups were not statistically significant ( p >0.05). In our experiment, the average peroxide value of fat in meat under storage conditions 9 months at -18°C was lower in the group with a share of 4% alfalfa meal 2.42 µmol O2.g -1 compared with an average value of peroxide number 5.79 µmol O2.g -1 in the control group. Medicago sativa L. is an interesting object for research. It is characterized by high content of protein and biologically active substances that are effective for the promotion of health, and also an improvement the nutritional value and technological properties of the poultry food, when is used in feed mixtures.